Green biodegradation: Analysis of potential polyurethane-degrading enzymes and their secretion in Chlamydomonas reinhardtii | Poster Board #161

Plastic pollution is one of the largest concerns of the 21st century, and conventional recycling methods are ineffective and contribute to the production of carbon emissions and microplastics. The increased abundance of micro and nanoplastics in food sources and humans themselves is of great concern since the effects of their presence is largely unknown. An alternative solution to traditional recycling is enzymatic degradation and molecular recycling of monomers of plastics. Polyester polyurethanes (PUs) are of particular interest due to the large percentage of products that contain these biodegradable polymers. Previous research done by our lab has shown that bio-based PU foams can biodegrade in compost, soil, and marine environments. Two particular species of bacteria associated with this biodegradation have been identified and individually cultured in media containing a PU foam as the sole carbon source. Here we have analyzed potential PU-degrading enzymes that were present in the supernatant of these cultures. These enzymes were isolated and tested for activity that cleaves ester bonds (one of 2 bonds found in PU products). Enzymes that were found to have activity were then transformed into C. reinhardtii in order to assess if algae can express and secrete them. Transformants were plated on agar plates containing a PU dispersion to determine their degradative capacity. Since lipids and starch from algae can be extracted to form plastic biopolymers, these algae could serve as a platform for enzymatic degradation while simultaneously contributing to the creation of new biodegradable bio-plastics and foams made from components of their biomass.